1. Field of the Disclosure
The present disclosure relates generally to printers, and more particularly, to a printhead for a printer and a method for assembling the printhead.
2. Description of the Related Art
For obtaining large print swaths, a printer typically includes a page wide printhead that has an array of narrow heater chips (ejection chip units). The width of such narrow heater chips may generally be less than about two millimeters. Further, each heater chip of the page wide printhead includes about four to five fluid (ink) channels for fluids (inks), such as Cyan-Magenta-Yellow-blacK (CMYK) or Cyan-Magenta-Yellow-blacK-blacK (CMYKK). The aforementioned fluid channels may typically have about 100 micron thick walls, and are configured in the form of closely packed fluid channels.
However, the closely packed fluid channels within the each heater chip are required to be fed by horizontal micro fluidic channels from widely separated fluid channels configured in a printhead base (such as a ceramic base). The widely separated fluid channels of the printhead base are further connected to fluid bottles (ink reservoirs) that provide fluid to the fluid channels of the printhead base. FIG. 1 depicts a partial exploded schematic view of a typical page wide printhead 100. As shown in FIG. 1, the page wide printhead 100 includes a plurality of heater chips 110. The heater chips 110 may be stitched together, as shown in FIG. 1. Further, the heater chips 110 along with a Printed Circuit Board (PCB) 120 are mounted on a thin Liquid Crystal Polymer (LCP) layer 130 by utilizing a layer 140 of an adhesive tape (such as a Polyimide tape). The PCB 120 may also be coupled to a flexible cable 160 that includes conductive traces. The thin LCP layer 130 is further attached to a thick LCP layer 150 and/or a printhead base (i.e., ceramic base).
The thin LCP layer 130 includes a plurality of horizontal micro fluidic channels (not numbered) that may be fabricated by utilizing a process called injection molding. Further, the layer 140 of the adhesive tape may be provided with laser drilled holes and is used for covering the thin LCP layer 130. Furthermore, the heater chips 110 are mounted directly on the layer 140 of the adhesive tape. However, such configuration of the thin LCP layer 130 and the heater chips 110 with the layer 140 of the adhesive tape in between is associated with various issues, such as a low thermal conductivity of the layer 140 of the adhesive tape to dissipate heat from the heater chips 110 with higher power. Further, the heater chips 110 are mounted on the layer 140 of the adhesive tape, which is a soft layer, and such an arrangement leads to an unavoidable heater chip bow (i.e., deformity in the structure of the heater chips 110). Furthermore, lower hydrophilicity of polymer conduct holes for the thin LCP layer 130 as opposed to that of silicon holes causes easier air bubble trapping or fluid (ink) clogging within the printhead 100. Furthermore, large alignment tolerance between the holes in the layer 140 of the adhesive tape and the horizontal micro fluidic channels in the thin LCP layer 130 during a lamination process remains another major issue.
Accordingly, there persists a need for an efficient printhead and a method for assembling the printhead to address the aforementioned issues related with heat dissipation from heater chips of the printhead, deformation of the heater chips, air bubble trapping/fluid (ink) clogging within the printhead, and alignment tolerances within the printhead.